1. Field of the Invention
The present invention relates to a flat display apparatus.
2. Description of the Related Art
Recently, as a display panel which is to be used in a flat display apparatus, a plasma display panel (hereinafter, abbreviated to PDP) in which row electrode pairs and column electrode pairs are arranged on inner faces of a pair of substrates that are opposed to each other via a discharge space, discharge cells are formed at intersections of the electrodes, and discharges are caused in the discharge cells to perform a display are being vigorously developed.
A flat display apparatus using such a PDP is employed in an image monitor of a large screen. In an image monitor, components such as a tuner which provides an image source, speakers which produce an audio output, and an audio circuit which controls an audio signal to drive the speakers are configured as separate devices.
Along with popularization of flat display apparatuses having a large screen in general families, also a flat display apparatus which is integrated with a large screen, a tuner, speakers, an audio circuit, and other components has been developed so as to be easily used as a household television receiver.
In such an integrated flat display apparatus, a panel driving unit which controls drawing on a display panel, speakers, an audio circuit which controls an audio signal to drive the speakers, and a tuner circuit which extracts an audio signal and a video signal to be reproduced are incorporated in an outer case which houses the display panel.
Hereinafter, an example of a conventional example of an integrated flat display apparatus will be described in detail with reference to FIG. 1. FIG. 1 shows a conventional integrated flat display apparatus using a PDP.
As shown in FIG. 1, a flat display apparatus 101 comprises an outer case 110 configured by: a front face frame 113 in which a front face cover made of glass or the like is placed in an opening; and a rear cover 111. The outer case 110 incorporates: a PDP 103 which is a flat display panel for displaying an image; a panel driving unit 105 which controls image formation on the PDP 103 on the basis of an input video signal; a source unit 108 comprising an audio circuit 106 which controls output signals to speakers 109 and the like on the basis of an input audio signal, and a tuner circuit 107 which tunes a received radio wave such as a TV wave, and which extracts the video signal to be supplied to the panel driving unit 105, and the audio signal to be supplied to the audio circuit 106; and a power supply unit 102 which supplies an electric power to the above circuits.
The PDP 103 is bonded and fixed by a double-sided adhesive tape to a chassis board 104 which is made of a metal, and which is placed behind the PDP. The chassis board 104 is fastened and fixed by screws or the like to an attachment portion (not shown) formed on the front face frame 113.
The panel driving unit 105, the source unit 108, and the power supply unit 102 are mounted on the back face of the chassis board 104.
Usually, the front face frame 113 is formed by an integral molded product of a synthetic resin. The rear cover 111 is an integral product covering the whole back face of the chassis board 104 on which the power supply unit 102, the panel driving unit 105, the source unit 108, and the like are mounted. In order to prevent leakage of electromagnetic waves from occurring, the rear cover is made of a metal (for example, see JP-A-2001-345586).
An amplifier unit (particularly, a power IC and the like which constitute a power amplifier) which is mounted in the audio circuit 106 generates a considerably large amount of heat. In the above-described structure in which also the audio circuit 106 is incorporated in the housing space of the panel driving unit 105, in order to prevent the heat generated by the audio circuit 106 from affecting the operation of the panel driving unit 105, it is essential to form, in the outer case 110, a heat radiation port for releasing the heat generated by the audio circuit 106 to the outside of the case, and dispose a cooling fan for forcedly discharging the atmosphere at a high temperature in the case, through the heat radiation port to the outside (depending on the cooling capacity of a fan, plural fans may be required).
When a cooling fan is disposed in a flat display apparatus, the production cost is raised by the increased number of components to be mounted. Moreover, there arises a problem in that the housing space in the case is reduced and the size of apparatus is increased. Furthermore, there is the possibility that operation sound of the cooling fan leaks to the outside of the apparatus to impair the quietness required in an audio apparatus, etc.
In the conventional flat display apparatus 101, the metal-made rear cover 111 has the integral structure which covers the whole area of the chassis board 104, and the size of the cover is large. Therefore, the apparatus has another problem in that the weight is increased.
Examples of the problems which are to be solved by the invention are that the necessity of disposing a cooling fan increases the size of an apparatus and impairs the quietness, and that the large size of the metal-made rear cover increases the weight of the apparatus.